What Causes Bedsores in Nursing Homes?

You learned that your loved one has a bedsore. Now you want to know why. You want to know if someone could have stopped it. Two-thirds of all pressure injuries occur in people over age 70 [PMC6530466]. Nursing home residents are among the most vulnerable. And in most cases, bed sores are caused by failures in care that were entirely preventable.

If your loved one developed a bedsore in a nursing home, the cause is almost always preventable. A free case evaluation can help you find out what went wrong.

Find Out What Went Wrong

How Bedsores Form

A bedsore begins with pressure. When a person sits or lies in one position for too long, their body weight presses skin and tissue against the surface beneath them. This pressure squeezes shut the tiny blood vessels (capillaries) that deliver oxygen to the tissue.

Blood flow stops when external pressure exceeds about 32 mmHg – the point at which capillaries close [NPIAP / AHRQ]. Once flow stops, the tissue downstream gets no oxygen or nutrients. Cells begin to die. The damage starts deep, at the bone-muscle interface, and works outward toward the surface.

The NPIAP describes this as a destructive cycle: direct cellular deformation triggers inflammation and cell death. This causes swelling and rising pressure inside the tissue. The swelling further restricts blood flow. The cycle feeds on itself.

This process can begin in as little as two hours of unrelieved pressure. That is why the standard of care requires nursing homes to reposition residents at least every two hours.

The Four Forces That Cause Bedsores

Four mechanical forces cause bed sores. Pressure is the primary cause. The other three – shear, friction, and moisture – make the damage worse.

Pressure

Pressure is the direct cause. The body’s weight compresses tissue against a mattress, wheelchair, or medical device. The heel is the most common site, accounting for 34.1 percent of all pressure injuries [PMC12599044]. The sacrum (lower back) and foot are the next most common.

Bony areas are most vulnerable because there is less padding between the bone and the skin. In a bed-bound resident who is not turned, pressure builds up over the same bony points hour after hour.

Shear

Shear happens when tissue layers slide in opposite directions. This occurs most often when the head of the bed is raised above 30 degrees and the resident’s body slides downward while the skin stays in place against the mattress [NPIAP]. The tissue between skin and bone stretches and tears internally.

Shear can damage deep blood vessels without any visible sign on the surface.

Friction

Friction is surface abrasion. It happens when skin rubs against sheets, clothing, or equipment during transfers or repositioning. Friction alone does not cause deep injury, but it breaks down the skin barrier. This makes the tissue more vulnerable to pressure and shear [NPIAP].

Dragging a resident across sheets instead of lifting them is a common cause of friction damage.

Moisture

Moisture from urine, stool, sweat, or wound drainage weakens the skin barrier through maceration. This process can begin within 10 to 15 minutes of moisture contact [PMC4048585]. Weakened skin tears more easily and is less able to resist pressure.

Incontinence-associated dermatitis (IAD) softens and erodes the outer skin layer. This dramatically increases vulnerability to all three other forces.

Who Is Most at Risk?

Certain factors make nursing home residents especially vulnerable to bed sores:

• Immobility. Residents who cannot reposition themselves depend entirely on staff. Immobility is the strongest single predictor of bedsores, carrying an odds ratio of 4.54 [PMC12599044].
• Malnutrition. Poor nutrition weakens tissue and slows healing. Malnutrition raises the risk of pressure injury three-fold [PMC12599044].
• Incontinence. Moisture from urine or stool weakens the skin. Incontinence-associated dermatitis creates a direct pathway to pressure injury.
• Advanced age. Older skin is thinner, less elastic, and heals more slowly. Two-thirds of pressure injuries occur in people over 70 [PMC6530466].
• Cognitive impairment. Residents with dementia may not feel or report pain. They may not shift their weight on their own.
• Sensory loss. Residents who cannot feel pressure – due to stroke, spinal cord injury, or neuropathy – cannot tell when tissue is being damaged.

Nursing homes use risk assessment tools like the Braden Scale and Norton Scale to identify these factors and create individualized prevention plans [PMC9690319]. When the assessment is not done, or the resulting plan is not followed, bedsores develop.

Medical Device-Related Pressure Injuries

Not all bedsores come from beds or wheelchairs. Medical device-related pressure injuries (MDRPI) arise from tubes, masks, casts, splints, and other devices that press against the skin.

These injuries develop from prolonged device use without repositioning, incorrect device sizing, improper application of adhesives, and failure to check for risk factors like swelling or poor circulation [PMC6534376].

MDRPI is a known and preventable cause of bedsores. The nursing home is responsible for monitoring every device that touches a resident’s skin.

Common devices that cause pressure injuries include oxygen masks, nasal cannulas, cervical collars, splints, and casts. Any device that presses against the skin needs to be repositioned, properly fitted, and regularly checked.

How Quickly Can a Bedsore Develop?

Many families are surprised by how fast bedsores can form. The tissue damage process begins when blood flow is cut off. Under sustained pressure, cells start dying within hours. Two hours of immobility in a bed-bound resident is enough to start the process.

That timeline is why the standard of care requires repositioning at least every two hours. A nursing home that does not have a repositioning schedule – or that has one but does not follow it – is allowing the conditions for bedsores to develop.

Once tissue damage begins, progression can be rapid. A Stage 1 bedsore (redness that does not fade) can advance to a Stage 2 open wound within days if pressure is not relieved. From there, the wound can deepen to Stage 3 and Stage 4 if the nursing home does not intervene.

For information on what bedsores look like at each stage, see our bedsore stages guide.

How Nursing Home Failures Cause Bedsores

The causes described above – pressure, shear, friction, moisture – are the physical mechanisms. But in a nursing home, the real cause is usually a failure of care. Common failures include:

• Not repositioning residents. A bed-bound resident who is not turned at least every two hours is at high risk.
• Inadequate staffing. When there are not enough aides to turn residents on schedule, bedsores develop.
• No risk assessment at admission. If the facility did not score the resident’s risk using the Braden Scale or a similar tool, it cannot create an effective prevention plan.
• Missing or generic care plans. A care plan that does not address the specific resident’s risk factors is inadequate.
• Poor nutrition programs. Residents with active wounds need increased protein and calories. If the facility is not providing this, wounds do not heal.
• Failure to respond to early signs. A Stage 1 bedsore is a warning. If the facility does not adjust the care plan at Stage 1, the wound progresses.
• Poor incontinence management. Residents who are not kept clean and dry develop weakened skin that is far more vulnerable to pressure damage. Moisture from urine or stool can begin breaking down skin within minutes.